New for the XB4 are these optional brass lower suspension holders from Xray. The main purpose of the brass holders is to provide additional weight down low to improve traction and stability while lowering the car’s CG. The suspension holders feature Integrated Suspension Settings™ (I.S.S.) which allows for quick & easy suspension geometry setting. This XRAY concept was first introduced in the original XB8 and now has been carried over to the 1/10 scale XB4. The holders are +2mm and fit both XB4 & XB4 2WD. Set of 2 pieces.